Are you able to ask your teacher?
Answer:
4x^2 -8
Step-by-step explanation:
f(x)=3x^2-9
g(x)=x^2+1
(f+g)(x)=3x^2-9 +x^2+1
Combine like terms
= 4x^2 -8

It is already in the simplest form. It can be written as 0.216 in decimal form (rounded to 6 decimal places).
Notice the corners; the corner on each triangle with one line is equivalent, and the same goes for the corner on each triangle with two lines, and the corner on each triangle with three lines. this is just a way to know which angles match up!
this means the answer would be:
D!
Answer:
126.25
Step-by-step explanation:
take 8.75 and multiply by 8 =70
take 8.75+2.50=11.25
11.25x5=56.25
56.25+70=126.25